SBIRS Satellite Nears Completion of Environmental Testing
OMAHA, Neb. —The long-awaited first satellite in the U.S. Air Force’s Space Based Infrared System (SBIRS) has encountered no troubles in the last few months of repeated exposure to extremely cold temperatures, and the testing should be complete Nov. 14, a Lockheed Martin official said.
SBIRS prime contractorof Sunnyvale, Calif., still has several satellite hardware and software qualification tasks to complete following the conclusion of thermal vacuum testing. The company is on track to deliver the satellite in the fourth quarter of 2010 in time for an early 2011 launch, Rick Ambrose, Lockheed Martin’s vice president for surveillance and navigation systems, said in a Nov. 4 interview here.
“We have had no new discoveries, and it’s gone very smoothly,” Ambrose said. “There are three thermal cycles, and we’re in the final cold phase. We’re taking some extra days at the end to re-thermal balance the satellite as we try to figure out how to shorten our test times for the satellites that follow.
“We’re real happy about it and so is the customer.”
SBIRS consists of missile-detecting infrared sensors hosted by classified satellites in highly elliptical orbits and dedicated satellites in geosynchronous orbits. Two of the hosted payloads are now on orbit, but none of the geosynchronous satellites has been launched. The program have been among the Air Force’s most troublesome of the last decade, exceeding its original cost estimate by some $7.5 billion and accruing more than an eight-year delay in launching the first satellite.
Among the recent troubles was a glitch that required the entire satellite software code to be rewritten at a cost of $750 million. The software was completed in June, but the company will continue putting it through rigorous tests to simulate extreme anomalies until February, Ambrose said.
The second geosynchronous satellite is undergoing eight weeks of baseline integrated system testing prior to entering thermal vacuum testing. The Air Force wants to put 14 months between the launch of the first and second dedicated satellites so that any problems found during the first satellite’s year of on-orbit testing can be corrected on the second satellite, Ambrose said.
During early development work on the third SBIRS satellite, the company found some electronic parts to contain low levels of tin, which can cause problems on orbit. These parts have been remanufactured and will be replaced on the first two satellites after they complete environmental testing.
Meanwhile, Lockheed Martin is on or ahead of schedule in the development of the next-generation GPS satellites, he said. The company was awarded a $3 billion prime contract in May 2008 to build the eight GPS 3 Block A satellites. The company finished the satellites’ preliminary design review in May and is progressing toward critical design review.
“We did assembly level [preliminary design review] first to lock in the design, because we didn’t want to make any changes to the design unless we had to,” Ambrose said. “There has not been a single [major program] change. We are very committed to delivering GPS 3 on time.”
The satellites are scheduled to begin launching in 2014, and Lockheed Martin has not burned through any of its schedule margin as it proceeds toward that goal, he said.
The second-to-last of the 21 satellites Lockheed Martin built under the current-generation GPS 2R program has encountered difficulties since it launched in March and has not yet entered service. The GPS 2RM-20 satellite was the first satellite to feature a new demonstration signal called L5, and the signal has been interfering with the satellite’s primary L1 and L2 signals. The problem will be fixed and the satellite will enter operations after the Air Force completes modifications to the ground systems to account for distortions to the primary signals, Ambrose said.
“The service did not press the satellite into operations because it isn’t needed right now,” he said. “They are taking a very systematic approach to make sure there’s no old user equipment that might be impacted.”